In the past, as extra-large work vehicles, dump trucks for carrying crushed rock at a mine or the like have been widely used. In such dump trucks, it is difficult for a driver to grasp the circumstances in the periphery of the work vehicle using side mirrors and the like since the vehicle width is remarkably wide in comparison with a typical vehicle, and in addition, the length from the front to back is long.
Therefore, a periphery monitoring system, which is provided with obstacle detection sensors, a monitor, and a controller which is connected to the obstacle detection sensors and the monitor, is proposed with the object of the circumstances in the periphery of the work vehicle being simply grasped by the driver (refer to US 2009/0259400 A1). In the periphery monitoring system, in a case where an obstacle is detected by the obstacle detection sensors, the driver is warned of the presence of the obstacle by the presence of the obstacle being displayed on the monitor.